US authorities on Wednesday arrested three Brooklyn, New York men, of Central Asian descent, and charged them with trying to help the Islamic State of Syria and Iraq.

One of them was arrested at JFK Airport where he was trying to board a flight for Turkey, on his way to Syria. The second man was to follow later. And the third was their financier.

If stopped from traveling, they were willing to kill President Barack Obama, gun down police officers and cause explosions, according to a state complaint filed in a New York court.

The three men were identified as Abdurasul Hasanovich Juraboev, 24, Abror Habibov, 30, — both of Uzbek descent — and Akhror Saidakhmetov, 19, a Kazakh.

Habibov runs kiosks in malls in many states that sell kitchenware and repair mobiles. Juraboaev worked for him once and was friends with Saidakhmetov, who was arrested at JFK.

“The flow of foreign fighters to Syria represents an evolving threat to our country and to our allies,” said US Attorney Loretta Lynch, who is awaiting confirmation as next attorney general.

Scores of foreign fighters are reported to have joined the ISIS from all over the world, including the west, most recently three British teenage girls reported missing since February 17.

The FBI came upon them last August during a routine sweep of jihadi social media sites, according to the criminal complaint. They were alerted by a post on hilofatnews.com, a site that canvassed support for ISIS among Uzbeks: “I am in USA now but we don’t have any arms. But is it possible to commit ourselves as dedicated martyrs anyway while here?”

“What I am saying is, to shoot Obama and then get shot ourselves, will it do? That will strike fear in the hearts of infidels,” the poster added, according to the complaint.

That post was traced — thanks to a “voluntary disclosure of records” — to an address in Brooklyn. FBI agents found Juraboev there and he owned up the post.

And he owned up every sentiment in the post.

Some experts said that was dumb — for giving away the plot and even bragging about it, but others found it as a stunning confirmation of a deep-seated disaffection.

“That he was willing to tell FBI agents (they had declared themselves to be FBI agents,) that he was willing to kill the president was stunning,” said an intelligence source.

Intelligence and security sources were also struck by ISIS’s reach in the US — evidenced in the recorded conversations of the financier, Habibov, cited in the complaint.

He cast around for donations for Saidakhmetov, the 19 year old, who was caught at JFK, in phone calls to unidentified people, who promised to come up with whatever was required.